What are biofuels? Are all forms of biofuels good?
Biofuels, a form of bioenergy used as transport fuel, can be made from a wide range of plant materials (biomass) such as sugar, wheat, vegetable oils, wood and straws. Those biofuels currently on the market are often made from conventional agricultural crops. They are sometimes referred to as ‘agrofuels’ due to their production from agricultural products.
Biofuels are only one form of energy made from biomass. Other forms of bioenergy, for example biogas, heat and electricity produced from biomass, generally have a higher efficiency with less associated environmental concerns compared with biofuels. If managed sustainably, bioenergy from renewable sources has its merits and is key to tackle global climate change.
Current biofuels are often called ‘first generation biofuels’ because they are made with relatively simple technologies. Bioethanol can be produced from any feedstocks that contain a high starch or sugar content such as corn (maize), wheat, sugarcane, and sugar beet. After fermentation and distillation, this bioethanol can be mixed with petrol/gasoline in various proportions for car use. Biodiesel, on the other hand, is made through transesterification of vegetable oil such as palm oil, rapeseed oil, soya bean oil and even used-cooking oil.
Even though such biofuels are made from plant material and hence are a renewable source, they are not as ‘green’ as they seem. To produce biofuels, large amount of land is need to cultivate the crop, together with irrigation, use of fertilizers, transportation, conversion and refinery processes, all these require energy input and emit carbon dioxide. There are a large and growing number of studies that suggest that the use of current biofuels would save very little greenhouse gas, destroy wildlife habitats, as well as affect indigenous and rural poor communities around the world. (more on their Impacts)
Due to the generally lower carbon emission and the greater possibility to use waste material, there are high hopes for so-called ‘second generation biofuels’, which are mainly made from non-edible feedstocks as lignocellulosic materials like wood and straw. However, the cost of converting such biomass into bioethanol or biodiesel or other types of transport fuels is still very high, and the technology still remains in the demonstration phase. Technological breakthroughs will be needed to bring the cost down, and depending on the technology it is estimated that second generation biofuels will not become fully commercial for several years to come and will need of significant government support (IEA 2008). There are also uncertainties about their potential to provide transport fuel in a large scale due to the logistical challenge of transporting biomass material to large production facilities (OECD, 2007). Moreover, they have their share of environmental concerns as their production can also involve the requirement of land which can lead to direct and indirect land use change.
It is important to indicate that the terminology of these fuel sources might be misleading, as it suggests that first-generation biofuels are a necessary first step to second generation or that the first are older than the second. On the contrary second generation biofuels were firstly developed in 1930 in Germany converting biomass to liquids and for the production of each of these an entire different infrastructure is needed.
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